Study Finds Direct Link Between Obesity, Heart Disease

Data from more than 75,000 people showed that having a higher BMI, in itself, is harmful

WEDNESDAY, May 2 (HealthDay News) -- A large new study is the first to show a direct link between a high body-mass index and the risk of developing heart disease, British and Danish researchers say.

Body-mass index (BMI) is a measurement based on height and weight. People with a BMI of 18.5 to 24.9 are normal weight while those with a BMI of 30 or more are obese. Those in between are deemed overweight.

For the study, the researchers analyzed data from more than 75,000 people in Copenhagen and found that those with a high BMI had a 26 percent increased risk of developing heart disease. Further analysis using genetic and other data showed that a BMI increase of 4 points increases the risk of heart disease by no less than 52 percent.

"By doing epidemiological studies combined with genetic analysis, we have been able to show in a group of nearly 76,000 persons that a high BMI is enough in itself to damage the heart," Borge Nordestgaard, chief physician at Copenhagen University Hospital, said in a university news release.

"Observational studies have also suggested a relationship between heart disease and obesity, but that is not enough to prove a direct correlation. Obese people can share characteristics or lifestyle traits that have an influence on both the heart and weight. Or there can be a reverse causality, that is, it is the diseased heart that causes obesity and not the other way round," said Nordestgaard, who is also a clinical professor in the health and medical sciences faculty at the university.

The study was published May 1 in the journal PLoS Medicine.

Study co-author Dr. Nicholas Timpson, a lecturer in genetic epidemiology at the University of Bristol in England, noted in the news release: "In light of rising obesity levels, these findings are fundamental to improving public health. Our research shows that shifting to a lifestyle that promotes a lower BMI -- even if it does nothing else -- will reduce the odds of developing the disease."